Anesthesia machine without carbon dioxide absorption tank
By using gas separation membrane technology to remove carbon dioxide from anesthesia machines, the problem of untimely replacement of carbon dioxide absorbents has been solved, achieving safe and efficient carbon dioxide removal and reducing the risks and costs of traditional absorbents.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-17
- Publication Date
- 2026-03-24
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
There is a lack of recognized standards for when to replace carbon dioxide absorbents in existing anesthesia machines, which leads to the risk of carbon dioxide re-inhalation. In addition, traditional absorbents have problems such as corrosiveness, pollution, and increased medical costs.
By employing gas separation membrane technology and utilizing carbon dioxide permeable membranes and molecular sieve membrane structures, carbon dioxide is removed through gas sieving and separation, thus avoiding dependence on traditional absorbents.
It achieves efficient removal of carbon dioxide, reduces medical risks and costs, reduces environmental pollution, and improves the safety and efficiency of the anesthesia process.
Smart Images
Figure CN224024011U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to anesthetizing breathing device technical field, concretely relates to a kind of carbon dioxide absorption tankless anesthesia machine. BACKGROUND
[0002] Most modern anesthesia machines adopt circulation closed or semi-closed breathing circuit when mechanical ventilation is used.In this kind of circuit, the carbon dioxide in the gas exhaled by the patient must be absorbed and removed by the carbon dioxide absorption device before returning to the breathing pipeline of the anesthesia machine again, so as to prevent the patient from repeatedly inhaling carbon dioxide and threatening life.
[0003] The commonly used carbon dioxide absorbent in clinic mainly includes sodium lime, calcium lime and barium lime, and its principle of action is to use carbon dioxide absorbent to react with carbon dioxide, thereby realizing the absorption of carbon dioxide.The humidity, temperature, fresh gas flow and ventilation volume of the gas in the circuit, as well as the type of breathing circuit of the anesthesia machine, affect the absorption efficiency of the carbon dioxide absorbent, and there is no recognized standard for the timing of replacing the carbon dioxide absorbent when the carbon dioxide absorbent is exhausted. ET When end-tidal carbon dioxide concentration (P
[0004] In addition, in order to ensure the safety of patient breathing, the anesthesia physician may also bring a series of risks by frequently replacing the carbon dioxide absorbent with active treatment measures, including damage or loss of tank parts, increased workload of anesthesia physicians, increased medical costs, increased toxic occupational exposure caused by chemical dust, increased chemical medical resource consumption, environmental pollution, etc.
[0005] In view of the above defects, the present application is proposed. CONTENT OF THE UTILITY MODEL
[0006] The utility model provides a kind of carbon dioxide absorption tankless anesthesia machine to the problems of carbon dioxide absorbent in existing anesthesia circuit.
[0007] In order to solve the problems in the above background art, the utility model provides the following technical solutions:
[0008] A carbon dioxide absorption tankless anesthesia machine includes a gas circulation circuit and a breathing machine connected to the gas circulation circuit, a patient end connection port is provided between the downstream side of the inspiratory unidirectional valve and the upstream side of the expiratory unidirectional valve for connecting the patient's respiratory tract, and a carbon dioxide removal device is provided between the downstream side of the expiratory unidirectional valve and the upstream side of the inspiratory unidirectional valve for removing the carbon dioxide exhaled by the patient in the breathing circuit.
[0009] The structure of the carbon dioxide removal device includes a gas screening tank and a gas separation membrane installed inside the gas screening tank. The gas separation membrane is a carbon dioxide permeable membrane used to separate carbon dioxide in the breathing circuit of an anesthesia machine from the gas. The gas separation membrane is connected to the breathing circuit through an air inlet and transports reusable gas from which carbon dioxide has been removed through a trapped gas outlet.
[0010] The structure of the carbon dioxide removal device also includes an alternative gas separation membrane and a pressure check valve. The alternative gas separation membrane is connected to the air inlet through the pressure check valve, and its trapped gas outlet is also connected to the breathing circuit. The permeation side of the alternative gas separation membrane is connected to the anesthesia waste gas removal system. When the patient's breathing volume is greater than a set threshold, the increased flow and pressure cause the check valve to open, and the alternative gas separation membrane separates carbon dioxide from the excess gas.
[0011] The material of the gas separation membrane is one of a molecular sieve membrane and a polymer membrane.
[0012] The material of the molecular sieve membrane is a high-silicon or full-silicon molecular sieve.
[0013] The support body of the molecular sieve membrane is a four-channel hollow fiber structure with a diameter of 1-5 mm.
[0014] The material of the support body of the molecular sieve membrane is alumina.
[0015] The structure of the carbon dioxide removal device also includes a volatile tank of anesthetic gas connected to the breathing machine for releasing anesthetic gas into the pipeline.
[0016] The anesthetic gas is selected from propofol, thiopental sodium, halothane, chloroform, lorazepam, phenobarbital, caffeine, etc.
[0017] Advantages
[0018] The gas separation membrane has a regular microporous structure, which can achieve precise molecular-scale screening. In particular, it exhibits excellent carbon dioxide gas permeability and separation selectivity in the separation of mixed gases containing carbon dioxide. The molecular sieve membrane is used as the material of the gas separation membrane, and four-channel hollow fiber alumina is used as the support body of the molecular sieve membrane, which is beneficial to improve the packing density of the membrane and facilitate the miniaturization of the carbon dioxide separation device.
[0019] The molecular sieve membrane has a high-silicon (or full-silicon) structure, strong hydrophobicity, good chemical stability and biocompatibility, which can prolong the service life of the membrane module, significantly reduce the application cost, and withstand high temperature, alcohol or ultraviolet disinfection and sterilization treatment, and has the advantage of regeneration and utilization. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 : A schematic diagram of the orthographic structure of this utility model.
[0021] 1. Air inlet; 2. Gas screening tank; 3. Gas separation membrane; 4. Retained gas outlet; 5. Interface for anesthetic waste gas removal system. Figure 2 Flowchart of the carbon dioxide removal device in an anesthesia machine.
[0022] 6. Air source; 7. Inspiratory check valve; 8. Inspiratory end; 9. Patient end; 10. Expiratory end; 11. Expiratory check valve; 12. Respiratory mode control switch; 13. APL valve; 14. Reservoir bag; 15. Ventilator; 16. Carbon dioxide removal device.
[0023] Figure 3 Experimental results of treating carbon dioxide using molecular sieve membranes under saturated water vapor conditions.
[0024] Figure 4 : Another structural diagram of a carbon dioxide removal device.
[0025] 1. Air inlet; 2. Gas screening tank; 3. Gas separation membrane; 4. Retained gas outlet; 5. Interface for anesthetic waste gas removal system; 17. Alternative gas separation membrane; 18. Pressure check valve. Detailed Implementation
[0026] To address the drawbacks of traditional anesthesia machines that use soda lime or barium lime as carbon dioxide absorbents, such as strong corrosiveness, easy dust pollution in the operating room, increased workload for anesthesia staff, and increased burden of medical waste disposal, this utility model employs a gas separation membrane. For example... Figure 1 As shown, the carbon dioxide removal device consists of an air inlet, a gas sieving tank, a gas separation membrane, a trapped gas outlet, and an interface for the anesthetic waste gas removal system. The patient's exhaled gas enters the gas sieving tank equipped with the gas separation membrane through the air inlet. Due to differences in the dynamic diameter, properties, and concentration of gases in the anesthetic circuit, such as oxygen, carbon dioxide, nitrogen, and anesthetic gases (e.g., sevoflurane), the gases are separated. Carbon dioxide passes through the gas separation membrane and is discharged from the circulation system, while the remaining gases are trapped in the anesthetic circuit and reused by the body.
[0027] More specifically, the carbon dioxide-free anesthesia machine in this embodiment includes a gas circulation circuit and a ventilator 15 connected to the gas circulation circuit. The circuit is provided with an inspiratory one-way valve 7 and an expiratory one-way valve 11. A patient-end connection port 9 is provided between the downstream side of the inspiratory one-way valve 7 and the upstream side of the expiratory one-way valve 11 for connecting to the patient's airway. A carbon dioxide removal device 16 is provided between the downstream side of the expiratory one-way valve 11 and the upstream side of the inspiratory one-way valve 7 for removing carbon dioxide exhaled by the patient from the breathing circuit.
[0028] The structure of the carbon dioxide removal device 16 includes a gas sieving tank 2 and a gas separation membrane 3 installed inside it. The gas separation membrane 3 is used to separate carbon dioxide in the breathing circuit of the anesthesia machine from the gas by passing through the membrane layer. The gas separation membrane 3 is connected to the breathing circuit through the air inlet 1 and delivers reusable gas with carbon dioxide removed by connecting the interception gas outlet 4.
[0029] The structure of the carbon dioxide removal device 16 further includes: a backup gas separation membrane 17 and a pressure check valve 18; the backup gas separation membrane 17 is connected to the air inlet 1 through the pressure check valve 18, and its intercepted gas outlet 4 is also connected to the breathing circuit. Its permeameter is connected to the interface 5 of the anesthetic waste gas removal system. When the patient's breathing volume is greater than the set threshold, the increased flow and pressure cause the check valve 18 to open, and the backup gas separation membrane 17 separates the remaining gas into carbon dioxide.
[0030] The carbon dioxide removal device 16 further includes: an anesthetic gas vaporizer connected to the ventilator for releasing anesthetic gas into the tubing.
[0031] Specific operation process:
[0032] (1) When a patient is ventilated by an anesthesia machine, the exhaled air enters the gas separation membrane assembly through the air inlet. Driven by the gas osmotic pressure, most of the carbon dioxide, a small amount of oxygen and nitrogen selectively permeate through the gas separation membrane and are discharged from the osmotic side. At the same time, most of the oxygen, nitrogen, anesthetic gas and a small amount of carbon dioxide that are retained are recovered from the retention side and mixed with fresh gas to continue to participate in human gas exchange and anesthesia.
[0033] (2) The gas passes through the hollow fiber molecular sieve membrane group, and the air source gas flow rate is adjusted by the inhalation one-way valve to deliver it to the patient end at a suitable oxygen permeation rate, and selectively separate the patient's exhaled gas.
[0034] like Figure 2 As shown in the complete gas exchange process diagram, carbon dioxide and oxygen enter the loop through the mass flow controller. The concentration of carbon dioxide and oxygen before gas separation is detected by the analysis equipment. After gas exchange through the membrane module, the concentration of carbon dioxide and oxygen on the interception side and the exhaust side is detected again.
[0035] The specific experimental procedure is as follows: a high-silica CHA molecular sieve membrane is used as the gas separation membrane. The inlet is controlled to contain 95% oxygen and 5% carbon dioxide under normal temperature and pressure (298K, 101kPa) humid conditions to simulate the patient's exhaled gas. The concentrations of oxygen and carbon dioxide on the inlet side, the interception side, and the exhaust side, as well as the separation performance, are calculated before and after gas separation.
[0036] Figure 3 The experimental results of the molecular sieve membrane treating carbon dioxide under saturated water vapor condition. The composition of the inlet gas is 5% carbon dioxide and 95% air. When the inlet gas flow is 50 mL / min, the carbon dioxide concentration after membrane separation is reduced to 0.2%. In the figure: left graph: abscissa: total gas flow; ordinate: carbon dioxide concentration on the retentate side; red line: carbon dioxide concentration; blue line: corrected carbon dioxide concentration. Right graph: abscissa: total gas flow; left ordinate: gas permeability; right ordinate: carbon dioxide concentration on the permeate side; blue line: permeate gas flow; red line: carbon dioxide concentration on the permeate side.
[0037] Figure 3 It can be seen that with the increase of the inlet gas flow, the carbon dioxide content on the retentate side also increases, and the carbon dioxide content on the permeate side decreases, which is mainly due to the limited processing load of the membrane. In another embodiment, the tank also includes an alternative gas separation membrane, which is connected to the gas inlet through a pressure check valve, and the retentate side is also connected to the breathing circuit, and the permeate side is connected to the waste gas outlet. When the patient's breathing gas flow is greater than the set threshold, the increased flow and pressure open the check valve, and the remaining gas is separated by the alternative gas separation membrane to avoid the problem of reduced separation effect caused by increased gas flow load.
[0038] As shown in Figure 3 The carbon dioxide and oxygen separation selectivity of the gas separation membrane is high, the mechanical strength is high, the properties are stable, the biocompatibility is good, and it is expected to become a material to replace traditional carbon dioxide absorbents such as sodium lime and barium lime.
[0039] Such a carbon dioxide removal device can be used as a fixed accessory of an anesthesia machine for a long time.
[0040] The embodiments of the present application are given for the purpose of example and description, and are not exhaustive or limit the present application to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present application, and to enable those of ordinary skill in the art to understand the present application so as to design various embodiments with various modifications suitable for specific purposes.
Claims
1. A carbon dioxide absorption tank-free anesthesia machine, characterized in that, it comprises a gas circulation loop, and a breathing machine (15) connected to the gas circulation loop, a gas inlet valve (7) and a gas outlet valve (11) are arranged in the loop, a patient end connecting port (9) is arranged between the downstream side of the gas inlet valve (7) and the upstream side of the gas outlet valve (11) for connecting the patient's respiratory tract; a carbon dioxide removal device (16) is arranged between the downstream side of the gas outlet valve (11) and the upstream side of the gas inlet valve (7) for removing the carbon dioxide exhaled by the patient in the breathing loop; the structure of the carbon dioxide removal device (16) comprises a gas separation tank (2) and a gas separation membrane (3) installed in the gas separation tank (2), the gas separation membrane (3) is a carbon dioxide permeable membrane, which is used for separating the carbon dioxide in the breathing loop of the anesthesia machine from the gas through the membrane layer; an air source (6) is arranged between the gas inlet valve (7) and the carbon dioxide removal device, the gas inlet valve (7) adjusts the air source gas flow to be suitable for the permeation rate of oxygen to the patient end; the structure of the carbon dioxide removal device (16) further comprises an alternative gas separation membrane (17) and a pressure check valve (18); the alternative gas separation membrane (17) is connected with the gas inlet port (1) through the pressure check valve (18), and the trapped gas outlet (4) thereof is also connected with the breathing loop in communication, and the permeation side thereof is connected with the anesthesia waste gas removal system interface (5); when the patient's breathing volume is greater than a set threshold, the increased flow and pressure make the check valve (18) open, and the alternative gas separation membrane (17) separates the carbon dioxide from the excess gas. The gas separation membrane (3) is connected with the breathing loop through the gas inlet port (1), and the reusable gas from which the carbon dioxide is removed is delivered through the connected trapped gas outlet (4).
2. The carbon dioxide-absorption-free canisterless anesthesia machine of claim 1, wherein, 3. The carbon dioxide absorption tank-free anesthesia machine according to claim 2, characterized in that, the material of the gas separation membrane (3) is one of a molecular sieve membrane and a polymer membrane.
4. The carbon dioxide absorption tank-free anesthesia machine according to claim 1, characterized in that, the material of the molecular sieve membrane is a high-silicon or full-silicon molecular sieve.
5. The carbon dioxide absorption tank-free anesthesia machine according to claim 4, characterized in that, the support body of the molecular sieve membrane is a four-channel hollow fiber structure, and the diameter of the hollow fiber structure is 1mm-5mm.
6. The carbon dioxide absorption tank-free anesthesia machine according to claim 4, characterized in that, the material of the support body of the molecular sieve membrane is alumina.
7. The carbon dioxide absorption tank-free anesthesia machine according to claim 1, characterized in that, the structure of the carbon dioxide removal device (16) further comprises a volatile tank of anesthetic gas connected to the breathing machine for releasing anesthetic gas into the pipeline.